1. Field of the Invention
The invention relates to an apparatus for readily sealingly engaging and selectively disengaging one end of a tubular member, such as a cylindrical leg extending downwardly onto the sea bed from the platform utilized in the drilling and completion of subterranean oil and gas wells.
2. Description of the Prior Art
Seal means defining a diaphragm element oftentimes are disposed upon the lowermost end of a platform leg for enabling flotation of the platform to an offshore location. When the platform approaches the desired location for leveling of the platform on the sea bed, the seal means are punctured, thus enabling a flood of water to enter into the leg whereby the legs thereafter rest upon the ocean floor. Additionally, such sealing means oftentimes are placed upon the lowermost end of a tubular member, such as a platform leg, to prevent contaminant, such as silt and gravel and other debris, from entering the tubular member prior to the insertion therethrough of a piling element for anchoring the sleeve with the sea bed. After the piling is inserted within the interior of the sleeve, the lower end of the piling contacts and engages the sealing means, whereby the sealing means is ruptured, permitting the piling to pass therethrough, with the inner edges of the sealing means acting as a wiper to remove particulate matter from the exterior of the piling and to prevent foreign matter, as well as liquid, from passing from below to above the diaphragm and within the annulus area thereabove between the piling and the sleeve, to enable a more effective grouting of the annulus to secure the piling to the sleeve. Such sealing means are well known to the art, and are typified by that disclosed in U.S. Pat. No. 3,533,241, to B. H. Bowerman, et al, entitled "Rupturable Seal Assembly For Piling Guides".
When utilizing such seal assemblies, it is highly desirable to provide controlled flooding of the interior of the sleeve by selective sealing disengagement of the seal means from the sleeve. Additionally, when a sleeve carrying a seal means is exposed to a high pressure environment, such as that found when a platform is to be landed at a comparatively deep water depth, oftentimes the seal means so utilized will be elastomerically reinforced, but will still be exposed to high pressures. Therefore, it is desirable to reduce the overall exposure of the seal means to such high pressure by providing a fluid tight element across the lower end of the tubular member, or sleeve, which is resistant to the effects of such high pressure.
The present invention provides considerable improvement over apparatuses utilized in the past by providing means somewhat less resistant to the effects of high pressure whereby the seal means may be selectively disengaged from the tubular member, or sleeve, to permit controlled flooding of the interior of the sleeve. The apparatus is of relatively simple construction and is comparatively inexpensive to manufacture and assemble.